At least 11 people have been arrested across the UK after allegedly trying to use social media sites such as Facebook to incite riots.

Riot policemen in front of a burning building in Croydon on Monday night: police have warned Facebook users against attempting to incite any further violence (Picture: AFP/Getty)

Essex police said today that they had arrested three teenagers – from South Ockendon, Clacton and Grays – who were suspected of using social networks and mobile phones to call for rioting, after police officers had been monitoring sites including Facebook for early warnings of possible unrest.

Dorset police said that they had arrested a 23-year-old man in Bournemouth on suspicion of incitement to riot, ‘following reports of information being forwarded by an electronic device regarding a potential planned disorder in the town centre.’

A 16-year-old boy was arrested by Strathclyde police yesterday afternoon on the south side of Glasgow after allegedly encouraging rioting on Facebook, and is due to appear at Glasgow Sheriff Court today.

Also in Scotland, Tayside police arrested an 18-year-old man over Facebook posts encouraging others to turn up in Dundee city centre with weapons to riot. The teenager is expected to appear at Dundee Sheriff Court today.

In Hastings, East Sussex, two men in their early twenties from nearby St Leonards-on-Sea were arrested on suspicion of public order offences. Police were tipped off that two men were allegedly trying to arrange trouble through Facebook, and made the arrests after a small group gathered outside in the town centre.

West Yorkshire Police said a 19-year-old woman has been arrested on suspicion of encouraging violent disorder after posting a Facebook invitation to a ‘riot’ in Wakefield.

And in Folkestone, Kent, two 18-year-olds were arrested in on suspicion of inciting rioting via Facebook, after Scotland Yard said a number of ‘inflammatory’ comments had been spotted on the social network.

Police warned social network users that they could face severe consequences for trying to spark further riots online.

Essex police’s acting Assistant Chief Constable Maurice Mason said: ‘We are watching social networking sites closely, and if there are any criminal offences being committed we will track down the people responsible and deal with them.’

And in Greater Manchester, which was badly hit by riots and looting in both Manchester city centre and Salford on Tuesday night, police issued their own warning over Twitter, writing on their official Twitter account : ‘If you have been using social networking sites to incite disorder, expect us to come knocking on your door very soon.’